In U.S. Pat. No. 4,962,115 there are described N-(3-hydroxy-4-piperidinyl)benzamide derivatives having gastro-intestinal motility stimulating activity. In JP-A-2-104572 there are also described benzamide derivatives having digestive tract hypergic action. EP-A-0,278,173 discloses the use of heterocyclic derivatives of among others which are benzoic acid, acting as 5HT.sub.3 -antagonists for treating depression. The present compounds differ structurally and show unexpectedly high affinity as ligands for the 5HT.sub.2 -receptor, yielding strong and specific 5HT.sub.2 -antagonism.